The "Obsessive Paradox": The Complex Relationship Between Cognitive and Obsessive Dimensions in Schizophrenia.

The objective of the study was to investigate the relationship between cognitive functions and obsessive-compulsive dimension in schizophrenia and a possible moderating effect of schizophrenia symptom dimensions on this association. Sixty-one schizophrenia patients were administered the Positive and Negative Syndrome Scale, the Yale-Brown Obsessive-Compulsive Scale (YBOCS), and the Matrics Consensus Cognitive Battery. A U-shaped curve described a gradual transition from an inverse association to a positive relationship between YBOCS and processing speed scores, along a severity gradient of obsessive dimension. This effect ("the obsessive paradox") was not moderated by other symptom dimensions. The present study suggests that severe obsessive-compulsive symptoms may participate to counterbalance processing speed impairment independently from other symptom dimensions. These results highlight the complexity of the relationship between cognitive and obsessive dimensions in schizophrenia.